A Plasmacytoma of the Lateral Pharyngeal Wall: A Diagnostic Enigma.

Plasmacytoma is a rare plasma cell dyscrasia that grows in bones or soft tissues such as the pharynx. Soft tissue plasmacytomas are rare, and a higher burden has been reported in the upper aero-digestive tract, often manifesting as hoarseness, dysphagia, or odynophagia. Due to their rarity, extramedullary plasmacytomas (EMPs) have unknown prognostic factors, and guidelines for optimal management are still lacking. However, radiation therapy and surgery have been used with positive outcomes. Herein, we describe a unique case of plasmacytoma of the pharyngeal tissue in a male patient with a history of HIV disease. The patient completed 28 sessions of radiation therapy, resulting in an improvement in his throat pain and hoarseness. Given the patient's age and lack of traditional risk factors for head and neck cancers, his hoarseness and odynophagia proved to be a diagnostic conundrum. Although infrequent, soft tissue plasmacytomas should be considered in the differential diagnosis of head and neck tumors.

Megalosplenia as an initial manifestation of multiple myeloma with a novel CYLD gene mutation: A case report and literature review.

INTRODUCTION: Megalosplenia in newly diagnosed multiple myeloma (MM) is extremely rare, posing diagnostic and therapeutic challenges due to its unusual location and clinical manifestations and lack of optimal therapeutic strategies. CASE PRESENTATION: A 65-year-old female who was previously healthy presented with a history of ecchymosis on her right leg accompanied by progressive fatigue for 2 weeks. She was admitted to our center in July 2019 due to thrombocytopenia. The patient presented with megalosplenia, anemia, monoclonal protein (λ-light chain type) in the serum and urine, and 45.6% malignant plasma cells in the bone marrow. Splenectomy was performed due to persistent splenomegaly after 3 cycles of the bortezomib plus dexamethasone regimen, and immunohistochemistry results indicated λ-plasmacytoma of the spleen. The same cytogenetic and molecular abnormalities, including t(14;16), 14q32 amplification, 16q32 amplification, 20q12 amplification, and a novel CYLD gene mutation, were identified using fluorescence in situ hybridization and next-generation sequencing in both bone marrow and spleen samples. Therefore, a diagnosis of MM (λ-light chain type, DS III, ISS III, R-ISS III, high-risk) with spleen infiltration was proposed. The patient did not achieve remission after induction treatment with bortezomib plus lenalidomide and dexamethasone or salvage therapy with daratumumab plus ixazomib and dexamethasone. However, she ultimately did achieve very good partial remission with a regimen of bendamustine plus lenalidomide and dexamethasone. Unfortunately, she died of pneumonia associated with chemotherapy. CONCLUSION: To our knowledge, only 8 cases of spleen plasmacytoma at MM diagnosis have been described previously. Extramedullary myeloma patients with spleen involvement at diagnosis are younger and that the condition is usually accompanied by splenic rupture with aggressive clinical features and poor prognosis. Further studies are needed to explore pathogenesis and effective therapies to prolong the survival of such patients.

Extramedullary Plasmacytoma of the Retroperitoneum Detected on 18 F-FDG PET/CT.

ABSTRACT: Solitary retroperitoneal extramedullary plasmacytoma is a rare neoplasm. A 67-year-old man presented with abdominal pain and left leg weakness. Abdominal CT revealed a large mass in the left retroperitoneum, which demonstrated increased metabolic activity on subsequent 18 F-FDG PET/CT imaging. Furthermore, the patient's serum protein electrophoresis showed positive M-protein results. Pathological examination of the biopsied specimen confirmed the diagnosis of extramedullary plasmacytoma.

Clinico-pathological profile of patients with plasma cell neoplasms with special reference to bone marrow fibrosis and amyloid deposition.

To clarify the significance of bone marrow fibrosis and amyloid deposition in plasma cell neoplasm, a retrospective cross-sectional study for a period of 3 years was conducted. Patients who underwent bone marrow aspiration and biopsy with suspicion of plasma cell neoplasms were included in the study. The bone marrow findings were correlated with clinical profile of the patient along with biochemical parameters, cytogenetics, Fluorescent in situ hybridization (FISH) wherever available. A total of 273 bone marrow aspirates and biopsies of patients with suspected plasma cell neoplasms were analyzed. There were 181 male patients and 92 female patients (Male: Female = 1.96: 1). There were 245 cases of multiple myeloma (89.7%), 8 cases of primary amyloidosis (2.9%) and 6 monoclonal gammopathy of undetermined significance (MGUS) (2.1%), 5 cases of plasmacytoma (1.8%) and 4 cases of smouldering myeloma (1.4%), 5 cases of POEMS syndrome (1.8%). Bone marrow fibrosis was noted in 12 patients at diagnosis (4.3%). Among the parameters studied, only the mean Hemoglobin was significantly low in patients with marrow fibrosis. Amyloid deposition in various organs including bone marrow, kidney, liver etc., were noted in 17 patients overall (6.2%). In conclusion, the incidence of fibrosis (4.3%) and amyloidosis (6.2%) associated with plasma cell neoplasms were much lower in our study as compared to published studies.

Myocardial plasma cell tumor with intratumoral amyloidosis in a dog.

A 12-year-old mixed breed dog was evaluated for marked hypercalcemia that was identified during assessment for acute polydipsia and polyuria. Physical examination identified a new grade II/VI left apical systolic murmur. A mass involving the left ventricular posterior wall and left atrium was identified by echocardiography, suggesting neoplastic invasion into the myocardium. The patient was euthanized, and post-mortem cardiac evaluation identified an intramyocardial amyloid-producing plasma cell tumor. Multiple myeloma was suspected but could not be confirmed due to the limited post-mortem evaluation. This case is the first report of myocardial amyloidosis in a dog with a myeloma-related disorder (MRD). Dogs with MRD and myocardial involvement may not exhibit clinical signs that localize to the cardiovascular system; therefore, echocardiography should be considered during the staging process.

FDG PET/CT Image of Extramedullary Plasmacytoma in the Anterior Mediastinum.

ABSTRACT: Extramedullary plasmacytoma in the anterior mediastinum is very rare. We report FDG PET/CT findings of anterior mediastinum extramedullary plasmacytoma in a 54-year-old woman. On FDG PET/CT, it presented as a solitary anterior mediastinum mass with increased FDG uptake. The final pathology supported a diagnosis of extramedullary plasmacytoma. This case hints us that extramedullary plasmacytoma should be regarded as a differential diagnosis when we encounter a solitary anterior mediastinum mass with intense FDG uptake.

MUM1/IRF4 immunolabeling of neoplastic Langerhans histiocytes in a putative case of canine Langerhans cell histiocytosis.

Langerhans cell histiocytosis is a systemic histiocytic proliferative disease with cutaneous manifestations which is well described in human medical literature and has relatively recently been reclassified as a neoplastic disorder. The diagnosis of canine Langerhans cell histiocytosis has been proposed in the veterinary literature to refer to a histiocytic proliferative disease in the dog with clinical and histopathologic features that mirror the human disease. However, reports that invoke this diagnosis are rare and often lack complete diagnostic characterization. This case report presents an extensive diagnostic investigation of a putative case of Langerhans cell histiocytosis in a 3-year-old male castrated Golden Retriever dog, including gross, cytologic, histopathologic, and immunohistochemical findings. Furthermore, we document that canine LCH may have positive immunolabeling for the transcription factor multiple myeloma oncogene 1/interferon regulatory factor 4 (MUM1/IRF4), which is classically used for the diagnosis of canine plasma cell neoplasms.

Rapidly Enlarging Parotid Mass in a Person Living with HIV: A Case of Multiple Myeloma with Extramedullary Plasmacytoma.

BACKGROUND The differential diagnosis for a parotid mass is broad, including infectious, autoimmune, and neoplastic etiologies. In people with HIV, regardless of viral suppression or immune status, neoplastic causes are more common. This report describes the evaluation of a woman with a large parotid mass, with an ultimate diagnosis of multiple myeloma with extramedullary plasmacytoma. CASE REPORT A 51-year-old woman with HIV infection presented with headache, weight loss, and right facial mass that was present for 5 years but more rapidly enlarging in the prior year. CD4 count was 234 cells/mL, and HIV RNA was 10 810 copies/mL. Physical examination was significant for a large deforming right-sided facial mass, decreased sensation in the V1 and V2 distributions, and right-sided ophthalmoplegia and ptosis. MRI and PET/CT scan confirmed a metabolically active large parotid mass with extension into the cavernous sinus. An IgG kappa monoclonal spike was present on serum protein electrophoresis. Incisional biopsy of the facial mass showed atypical lymphoid cells with plasmablastic and plasmacytic morphology with a high mitotic rate and proliferation index. She was diagnosed with R-ISS stage II IgG kappa multiple myeloma with extramedullary plasmacytoma, and initiated on chemotherapy, radiation, and antiretroviral therapy. CONCLUSIONS A rapidly enlarging parotid mass should prompt timely evaluation and biopsy for definitive diagnosis, particularly in immunocompromised patients, including people with HIV. Extramedullary plasmacytomas have a more aggressive disease process in people with HIV and are associated with high-risk multiple myeloma and progression, as seen in this patient.

Plasmacytoma of the Head and Neck: Case Series and Review of the Literature.

Solitary plasmacytoma is a rare neoplasm characterized by localized proliferation of monoclonal plasma cells and is classified as solitary bone or solitary extramedullary plasmacytoma. Here, we present two rare cases of plasmacytoma of the head and neck. The first is a 78-year-old male who presented with a 3-month history of epistaxis and progressive obstruction of the right nasal passage. Computerized tomography (CT) imaging revealed a mass in the right nasal cavity with destruction to the maxillary sinus. An excisional biopsy was performed revealing anaplastic plasmacytoma. The second is a 64-year-old male with a past medical history significant for prostate cancer who presented with a 2-month history of left ear pain and progressive non-tender temporal swelling. A PET/CT revealed a highly avid, destructive, and lytic left temporal mass with no other evidence of distant disease. A left temporal craniectomy and infratemporal fossa dissection revealed plasma cell dyscrasia with monoclonal lambda in situ hybridization. Although plasmacytomas are uncommon tumors of the head and neck, they may mimic other entities that require different treatment. Prompt and accurate diagnosis is critical for appropriate therapeutic decisions and prognosis.

FAM46C-mediated tumor heterogeneity predicts extramedullary metastasis and poorer survival in multiple myeloma.

Cancers originate from a single cell according to Nowell's theory of clonal evolution. The enrichment of the most aggressive clones has been developed and the heterogeneity arises for genomic instability and environmental selection. Multiple myeloma (MM) is a multiple relapse plasma cell cancer generated from bone marrow. Although there were accumulating researches in multiple myeloma pathogenesis, the heterogeneity remains poorly understood. The participants enrolled in this study were 4 EMP+ (EMP, Extramedullary plasmacytoma) and 2 EMP- primarily untreated MM patients. Single cell RNA sequencing and analysis were conducted for the single cell suspension, which was sorted by flow cytometry from peripheral blood mononuclear cells or bone marrow cells. In our research, the results of single cell RNA sequencing show that FAM46C determines MM tumor heterogeneity predicting extramedullary metastasis by influencing RNA stability. Further, we integrated and analyzed 2280 multiple myeloma samples from 7 independent datasets, which uncover that FAM46C mediated tumor heterogeneity predicts poorer survival in multiple myeloma.

Ovarian plasmacytoma: a case report.

Plasmacytomas are a rare spectrum of plasma cell neoplasms that are single localized tumours, lacking the clinical features of plasma cell myeloma with no radiographical evidence of additional plasma cell tumours. Two clinical variants of plasmacytomas can be distinguished: solitary plasmacytoma of bone and extramedullary (or extraosseous) plasmacytoma. The latter is rare, representing 1% of all plasma cell neoplasms, occurring most frequently in the upper airways. Ovarian localization is exceptional, with only a few cases being reported in the literature. We herein report a case of an ovarian extramedullary plasmacytoma occurring in a 56-year-old woman who consulted for abdominal pain and abdominal mass, while highlighting the main histological and immunohistochemical features of this rare malignancy, along with a thorough review of literature gathering all cases of ovarian plasmacytomas reported to date.

[Recent Research Progress of Extramedullary Plasmacytoma --Review].

Extramedullary plasma cell tumor (EMP) is a kind of plasma cell tumor, and its pathogenesis is not completely clear. According to whether it is independent of myeloma disease, it can be divided into primary and secondary EMP, which have different biological and clinical characteristics. Primary EMP has low invasion, fewer cytogenetic and molecular genetic abnormalities and good prognosis, and surgery and / or radiotherapy are the mainly treatments. Secondary EMP, as the extramedullary invasive progression of multiple myeloma (MM), is often accompanied by high-risk cellular and molecular genetic abnormalities and poor prognosis, chemotherapy, immunotherapy and hematopoietic stem cell transplantation are the mainly treatment. This paper reviews the latest research progress of EMP in the pathogenesis, cytogenetics molecular genetics and treatment, so as to provide reference for clinical work.

Loss of Heterozygosity in the Circulating Tumor DNA and CD138+ Bone Marrow Cells in Multiple Myeloma.

Multiple myeloma (MM) is characterized by heterogeneity of tumor cells. The study of tumor cells from blood, bone marrow, plasmacytoma, etc., allows us to identify similarities and differences in tumor lesions of various anatomical localizations. The aim of this study was to compare the loss of heterozygosity (LOH) by tumor cells by assessing STR profiles of different MM lesions. We examined paired samples of plasma circulating tumor DNA (ctDNA) and CD138+ bone marrow cells in MM patients. For patients with plasmacytomas (66% of 38 patients included), the STR profile of plasmacytomas was also studied when biopsy samples were available. Diverse patterns of LOH were found in lesions of different localization for most patients. LOH in plasma ctDNA, bone marrow, and plasmacytoma samples was found for 55%, 71%, and 100% of patients, respectively. One could expect a greater variety of STR profiles in aberrant loci for patients with plasmacytomas. This hypothesis was not confirmed-no difference in the frequency of LOH in MM patients with or without plasmacytomas was found. This indicates the genetic diversity of tumor clones in MM, regardless of the presence of extramedullar lesions. Therefore, we conclude that risk stratification based on molecular tests performed solely on bone marrow samples may not be sufficient for all MM patients, including those without plasmacytomas. Due to genetic heterogeneity of MM tumor cells from various lesions, the high diagnostic value of liquid biopsy approaches becomes obvious.

Multiple Myeloma in a Young Adult: A Case Report.

CASE: We present a 27-year-old man who presented with worsened back pain after a fall from a ladder. Unrelenting pain prompted the discovery through imaging and biopsy of a large pelvic plasmacytoma along with innumerable axial and appendicular lytic osseous lesions. The patient was soon thereafter diagnosed with light chain multiple myeloma (MM) and underwent measurable residual disease response-adapted consolidation treatment. CONCLUSION: The typical age at diagnosis for MM is 60 to 70 years. This case emphasizes the need to consider MM when diagnosing patients younger than 30 years, especially those with numerous bony lesions.

Solitary extramedullary plasmacytoma of the left main bronchus: A case report and literature review.

Tracheal tumors are rare, accounting for 0.1% of all malignancies. Squamous cell carcinoma and adenoid cystic carcinoma are the two most prevalent tracheal cancers. Less than 20 cases of extramedullary plasmacytoma in the trachea and main bronchus have ever been documented in the literature, making it extremely uncommon. Although the origin of these lesions is unclear, viral pathogenesis and persistent inflammation are thought to be the main causes. Clinically, these individuals exhibit vague symptoms such as stridor, a persistent cough, dyspnea, or wheezing, making a correct diagnosis difficult.

The Prevalence of Epstein-Barr Virus in Plasma Cell Neoplasms is Higher in HIV-Positive Individuals.

AIMS: Epstein-Barr virus (EBV) is causally associated with many hematolymphoid malignancies. This laboratory-based study aimed to establish the prevalence of EBV in plasma cell neoplasms in a large South African cohort and to determine whether there is any correlation between EBV-positivity and human immunodeficiency virus (HIV) status in patients with plasma cell neoplasms, including plasma cell myeloma and plasmacytoma (solitary plasmacytoma of bone and extraosseous plasmacytoma). METHODS: This single-institution retrospective study included all patients with a histopathologic diagnosis of plasma cell neoplasm between 2003 and 2020. EBV-expression in the plasma cell neoplasms was assessed by EBV-encoded RNA (EBER) in situ hybridization (ISH) and correlated with HIV status. HIV status was determined by retrieving prior serologic results. Formalin-fixed paraffin-embedded tissue from HIV-unknown patients underwent HIV-1 p24 antibody testing. RESULTS: Sixteen of 89 plasma cell neoplasms (18%) were EBV-positive. There was a significant correlation between EBV and HIV infection in plasma cell neoplasms, with 6/10 tumors from HIV positive patients showing EBV-positivity in tumor cells. The EBV-positive cohort was significantly younger than the EBV-negative group. CONCLUSION: EBV-positivity in plasma cell neoplasms in this study is higher than previously reported. The significant occurrence of EBV in plasma cell neoplasms from HIV-positive patients suggests a co-carcinogenic relationship between the two viruses.

Airway and Hemodynamic Considerations for the Anesthetic Management of an Intraluminal Tracheal Plasmacytoma.

Central airway obstruction due to tracheal tumors presents unique challenges to the anesthesiologist. We present the case of a 44-year-old male taken to the OR for biopsy and resection of an undiagnosed tracheal mass. Intraoperative management was complicated by bleeding and significant hemodynamic instability, necessitating rapid surgical and anesthetic intervention. This ultimately led to abortion of surgical resection. Pathologic examination revealed a primary tracheal plasmacytoma, a rare type of tracheal tumor. Here, we describe anesthetic and hemodynamic considerations for a tracheal plasmacytoma. We discuss the approach to airway management in variable intrathoracic tracheal obstruction and the unpredictability of tracheal tumors.

A series of heterogeneous lymphoproliferative diseases with CD3 and MUM1 co-expressed in cats and dogs.

Lymphoma diagnosis in dogs and cats is continually evolving as new subtypes and human correlates are being recognized. In humans, T-cell lymphomas with MUM1 expressed and plasma cell neoplasia or B-cell lymphomas with CD3 expressed aberrantly are reported only rarely. We report here a case series of tumors in dogs and cats with CD3 and MUM1 co-expressed as determined by immunocytochemistry or immunohistochemistry. Lineage was assigned for these tumors by 3 board-certified pathologists and a veterinary immunologist based on review of clinical and cellular features and the results of ancillary testing including PCR for antigen receptor rearrangements, flow cytometry, and serum protein electrophoresis with immunofixation. In cats, 7 of 7 tumors, and in dogs, 3 of 6 tumors with CD3 and MUM1 co-expressed had clonal rearrangement of the immunoglobulin gene or serum monoclonal immunoglobulin, consistent with a diagnosis of a plasma cell neoplasia or myeloma-related disorder with CD3 expressed aberrantly. Disease was often disseminated; notably, 3 of 7 feline cases had cutaneous and/or subcutaneous involvement in the tarsal area. In dogs, 3 of 6 cases had a clonal T-cell receptor gamma result and no clonal immunoglobulin gene rearrangement and were diagnosed as a T-cell tumor with MUM1 expressed. The use of multiple testing modalities in our series of tumors with plasma-cell and T-cell antigens in dogs and cats aided in the comprehensive identification of the lymphoproliferative disease subtype.

Clinical Presentation and Outcome of Sinonasal Extraosseous Plasmacytoma in Denmark: A Nationwide Cohort From 1980 to 2017.

OBJECTIVES: Extraosseous plasmacytoma (EOP) is a rare plasma cell neoplasm that tends to convert to plasma cell myeloma (PCM) in about 11% to 35% of cases. It has a predilection for the upper respiratory tract, prototypically affecting the nasal cavity and paranasal sinuses. Contemporary first-line treatment is radiotherapy, with more recent studies showing an added benefit of combining radiation with surgery. In this cohort study, we aimed to examine clinical presentation, treatment, and prognosis for all patients nationwide from 1980 through 2017. Furthermore, we determined the size and extension of tumors, investigating the rate at which minimally invasive surgery would have been possible. METHODS: Patients were found in the national pathology registry, and all biopsies were collected for pathology review by a hematopathologist. We performed survival statistics for overall survival (OS), progression-free survival (PFS), and the cumulative incidence of conversion to PCM. RESULTS: Twenty-three patients were included. The median age was 65, and patients were primarily men (78%). Tumors were located in either the nasal cavity (57%), maxillary sinus (39%), or sphenoid sinus (4%). In most cases, the tumor was <5 cm (65%) without extension to adjacent structures (60%). The national incidence was 0.02/100,000 person-years, the median symptom duration until diagnosis was 5 months, and none of the patients presented with contiguous spread to regional lymph nodes. Stand-alone radiotherapy was the predominant treatment (61%). In the entire cohort, one patient died from the initial disease, and six patients died from either relapse of EOP or PCM. The 5-year OS, PFS, and conversion rate to PCM were 78%, 56%, and 23%, respectively. CONCLUSION: SN-EOP responds well to radiotherapy, but relapse and conversion to PCM were not uncommon and entailed a poor prognosis. Most tumors were endoscopically resectable and non-invasive, making the majority of tumors suitable for surgery as an addition to radiation.